GARNKERK,
Silica, |
53
| parts,
|
Alumina, |
43
| "
|
Lime, |
1
| "
|
Iron, |
1
| "
|
FRENCH,
Silica, |
40
| parts,
|
Alumina, |
31
| "
|
Iron, |
3
| "
|
WESTERN,
Silica, |
49 to 52
| parts,
|
Alumina, |
31 to 32
| "
|
Iron, |
2 to 4
| "
|
FUEL.
The subject deserves special notice. We have
said that the New England manufacturers at first used wood only, which
was prepared by being split into equal lengths, with an average diameter
of two inches, and then kiln-dried to dispel the sap and moisture. This
fuel was supplied to the furnace at opposite fire-holes, a stick at a
time, which was a laborious and heating process.
Subsequently, a furnace was built at South Boston,
over a cave, and unkilned wood was used in clefts. This saved one quarter
in fuel, but it used up the pots so rapidly as to prove to be no economy
in the end. After the development of the Virginia coal mines, our furnaces
were altered to use coal, which proved to be more convenient and less
costly than wood. The Pictou and Cumberland mines also increased the
supply; and at present all the furnaces in New England, with one exception,
are run with this last-named fuel.
The various experiments made to economize fuel
for the "glory-holes," as the workmen call the working places above
|